1. Field of the Invention.
The present invention relates to a resin system and more particularly to a resin system for filament winding of pressure vessels.
Description of the Prior Art.
In building filament wound high strength pressure vessels, such as for production rocket motors, it is necessary to use a resin system including binders and curing agents that are workable during the filament winding process and then properly harden to seal and retain the filaments in place. The filament material, for example, Kevlar, preferably has low weight, high strength, high temperature resistance and inert characteristics. Several different characteristics are needed in a resin system used for the complex filament winding of large pressure vessels for rocket motors. One such characteristic is that it have a long working life. Another is that it have suitable viscosity during the working process. Still another is that it cure properly after having been fully wound. It has been found that no single epoxy has all of the required characteristics.
The present invention overcomes these problems by providing a resin system having a plurality of different epoxies and curing agents that provide improved working and strength characteristics for the manufacture of complex filament wound pressure vessels.